Intracellular expression of a host-selective toxin, ToxA, in diverse plants phenocopies silencing of a ToxA-interacting protein, ToxABP1
Intracellular expression of a host-selective toxin, ToxA, in diverse plants phenocopies silencing of a ToxA-interacting protein, ToxABP1
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DOI：
10.1111/j.1469-8137.2010.03363.x
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发表时间：
2010-01-01
期刊：
影响因子：
9.4
通讯作者：
Ciuffetti, Lynda M.
中科院分区：
文献类型：
--
作者：
Manning, Viola A.;Chu, Ashley L.;Ciuffetti, Lynda M.
P>ToxA是小麦的一种宿主选择性毒素，可以在ToxA敏感的叶肉细胞内检测到，它定位于叶绿体并诱导坏死。ToxA与叶绿体定位蛋白ToxABP 1的相互作用涉及这一过程。因此，我们假设ToxABP 1在小麦中的沉默将导致坏死表型。另外，由于ToxABP 1在植物中高度保守，因此ToxA在通常不内化ToxA的植物中的内部表达应导致细胞死亡。对BSMV系统进行了修饰，以用作单子叶植物中ToxA的内部表达载体。本研究还利用农杆菌介导的ToxA基因在双子叶烟草（烟草-本氏烟）中的表达，病毒诱导的ToxABP 1基因沉默部分再现了ToxA处理的表型，ToxABP 1基因表达降低的小麦植株对ToxA的敏感性也降低。当ToxA在对ToxA不敏感的小麦、大麦和烟草中表达时，细胞死亡将随之发生，ToxA在任何含有叶绿体的细胞中积累都可能导致细胞死亡。我们的数据表明，ToxA-ToxABP 1相互作用改变了ToxABP 1的功能。这种相互作用是ToxA诱导的细胞死亡级联反应的关键（尽管不是唯一的）组分。
P>ToxA, a host-selective toxin of wheat, can be detected within ToxA-sensitive mesophyll cells, where it localizes to chloroplasts and induces necrosis. Interaction of ToxA with the chloroplast-localized protein ToxABP1 has been implicated in this process. Therefore, we hypothesized that silencing of ToxABP1 in wheat would lead to a necrotic phenotype. Also, because ToxABP1 is highly conserved in plants, internal expression of ToxA in plants that do not normally internalize ToxA should result in cell death.Reduction of ToxABP1 expression was achieved using Barley stripe mosaic virus (BSMV)-mediated, viral-induced gene silencing. The BSMV system was modified for use as an internal expression vector for ToxA in monocots. Agrobacterium-mediated expression of ToxA in a dicot (tobacco-Nicotiana benthamiana) was also performed.Viral-induced gene silencing of ToxABP1 partially recapitulates the phenotype of ToxA treatment and wheat plants with reduced ToxABP1 also have reduced sensitivity to ToxA. When ToxA is expressed in ToxA-insensitive wheat, barley (Hordeum vulgare) and tobacco, cell death ensues.ToxA accumulation in any chloroplast-containing cell is likely to result in cell death. Our data indicate that the ToxA-ToxABP1 interaction alters ToxABP1 function. This interaction is a critical, although not exclusive, component of the ToxA-induced cell death cascade.